基于正交试验的气密特殊螺纹油管接头密封性能研究

开发深海油气需要钻探大量超深井、大位移井，井下油管需要承受水下复合载荷的综合作用，这对气密特殊螺纹油管接头的密封性能提出挑战。以?99.25 mm×6.45 mm气密油管特殊螺纹接头为研究对象，以密封面最大接触压力为考核指标，依据ISO 13679标准A系试验载荷包络线对正交优化试验结果进行密封性能分析。分析结果表明：密封面最大接触压力影响因素敏感性由大至小的顺序为：密封面角度>扭矩台肩角度>螺纹承载面角度>螺纹锥度>螺纹螺距；气密特殊螺纹油管接头参数最优组合为密封面角度10°、扭矩台肩角度-12°、螺纹承载面角度12°、螺纹锥度1∶18、螺纹螺距4.8 mm;优组后油管接头在ISO 13679标准A系试验载荷下各加载点密封性能良好。所得结果对气密特殊螺纹油管结构的进一步优化设计具有指导意义。

Research on Sealing Performance of Gas-tight Special Thread Tubing Joint Based on Orthogonal Test

The development of deep-sea oil and gas requires drilling a large number of ultra-deep wells and large displacement wells. The underground tubing needs to bear the combined effect of underwater composite load, which poses a challenge to the sealing performance of gas-tight special thread tubing joints. In this paper, ø99.25 mm × 6.45 mm special thread joint of gas-tight tubing is taken as the research object, the maximum contact stress of sealing surface is taken as the evaluation index, and the sealing performance of orthogonal optimization test results is analyzed according to ISO 13679 A series load envelope load. The results show that the sensitivity of the maximum contact stress influencing factors on the sealing surface is as follows: sealing surface angle>torque shoulder angle>thread bearing surface angle>thread taper>thread pitch; The optimal combination of special gas-tight threads is as follows: sealing surface angle is 10°, torque shoulder angle is -12°, thread bearing surface angle is 12°, thread taper is 1:18, thread pitch is 4.8 mm; The sealing performance of the optimal combination oil pipe joint at each load loading point is excellent in ISO 13679 A series test. This paper has guiding significance for the further design and optimization of the gas-tight special thread tubing structure.